"I had come back into the office after being out in the classrooms, checked my e-mail and saw that it was there," said Ms. Trivelas, of the message containing the school's absolute rating of excellent, an accomplishment it has attained for the fifth year in a row. "It's always such a relief."

Ninety-two percent of Aiken County's schools in 2005 received an overall grade of average to excellent, while numerous schools went a step further by repeating their high level of performance for another year.

The absolute rating is based on how well pupils perform on the Palmetto Achievement Challenge Test in elementary school and on the High School Assessment Program exit exam in high school.

Like Chukker Creek, Aiken Elementary and Millbrook Elementary earned excellent ratings in 2005 for the fifth year in a row, while Silver Bluff High School has attained the rating for three years in a row.

Frank G. Roberson, the associate superintendent of instruction for the county, said the results could be attributed to the culture of excellence at the schools.

"I am extremely impressed with these schools," Dr. Roberson said. "These students are taking the opportunities to learn quite seriously because a vast majority of them are excelling."

Dr. Roberson said the schools that have attained good ratings also should be commended. "I don't want to give the impression we're not impressed with their level of performance, either," he said. "There's a small arithmetic difference between the grades from good to excellent."

Warren Whitson, the principal of Silver Bluff High School, said Silver Bluff's achievement of an absolute rating of excellent for the third year was a cooperative endeavor.

"It was a school-wide effort on the part of teachers, students, parents and community," Mr. Whitson said.